Special CIMS Seminar, Harvard University, 8/30/04

[James Houlahan <jahoulah physics harvard edu>]

Title: Special CIMS Seminar, Harvard University, 8/30/04

Monday, August 30

Special Seminar

Center for Imaging And Mesoscale Structures (Harvard University)

"Giant Nonlinear Effects in Cluster Sputtering of Heavy Metals: Physics and Applications"

Hans Henrik Anderson

(The Neils Bohr Institute, University of Copenhagen)

Monday, August 30, 2004

11:00 AM

Maxwell Dworkin building, Room 119 (2nd floor)

33 Oxford Street

Harvard University

Cambridge, MA

Abstract:      
The irradiation of Pb, Au and Ag with large gold clusters results in massive non-linear effects in the sputtering yields.  1.3 MeV Au11 sputter some 17,000 atoms off a silver surface, while the gold atoms, arriving individually at the same velocity as the cluster, will sputter only 550 atoms in total.  While linear sputtering has its maximum at an energy corresponding to the maximum in the nuclear stopping power, the non-linear sputtering maximize at approximately a third of that energy.  Interpretations in the form of evaporation from thermal spikes, fountain jets and shock-wave ejection of chunks will be discussed.

The possibilities for utilizing keV to MeV cluster beams in microelectronics technology and for analytical applications will also be mentioned.